I. Field of the Invention
This invention relates generally to a surgical procedure for treating an obstructed blood vessel and more particularly to a novel method of performing an endarterectomy in which ultrasonic energy is applied between the adventitia and the obstructing atheroma to facilitate the loosening thereof.
II. Description of the Prior Art
In treating atherosclerosis, one accepted method is the surgical excision of the atheroma from the interior wall of the affected blood vessel through an incision made into the blood vessel (arteriotomy) at the site of the lesion. The procedure is generally referred to as an endarterectomy.
A variety of surgical implements have been developed for facilitating this procedure. In this regard, reference is made to the Curi U.S. Pat. No. 3,939,138; Fogarty U.S. Pat. No. 4,287,890; Fogarty U.S. Pat. No. 4,621,636, Chiulli U.S. Pat. No. 4,038,985, Chin U.S. Pat. No. 4,559,927 and Chin U.S. Pat. No. 4,574,781. The use of these implements have met with varying degree of success in removing stenotic lesions.
It is important that when the lesion is loosened from the adventitia that it remains intact and that small particles thereof do not break loose and float to a location where an occlusion may result in serious ischemia. For example, in performing an endarterectomy on a coronary blood vessel, a blockage may result in a life-threatening infarct. When a carotid artery is involved, a small fragment of the lesion may embolize float to a tiny blood vessel in the brain precipitating a stroke or death. Moreover, the endarterectomy procedure can only be performed by surgeons of significant knowledge and utmost skill.